Microsoft exchange server problems / questions

Dr Zoidberg · 5 Nov 2007 at 18:06

Hi

Hoping this is better off in here than in the software section but i might be wrong.

As i think i have mentioned in a few questions over the last month or so i am looking after our IT matters whilst our main person is off. i few things have been a bit of a learning curve as it isnt my main job and i dont have any 'on the job' experience out side of what i was already doing here.

The situation i have at the moment is with our exchange server.

The main problem seems to be with our ISP and some one has been in touch with them and they have said they have problems with there email system, the last response was 'can you not just send one email at a time'
Now for a business broadband package from a large company this seems a bit bad, but its not up to me to ditch them.

The problem has been on going for 4 to 6 weeks now, with the last week being the worst.

Email is getting stuck in our outbound queue, the virtual SMTP server keeps dropping and having to be manually stopped and re-started.

I have been trying to manage the queue to some extent over this time, but last week being the end of the month my main job had to take priority and wednesday the email queue was left alone, by the end of the day over 150 emails were sat there.
Today there is still email sat there from last tuesday,

Small email (<10kb) seems to go as long as the SMTP server is up.
Once you start to get above this size it is really having problems, and once the queue gets longer the SMTP server falls over more often, so a lot of the time i have large amounts of the queue frozen which is helping, and letting 10 or 20 mails at a time have a go at getting out.

Now from our ISP it seems there system is struggling to take more than one email at a time, how often it can take one i have no idea, but i would have thought it has to be at a decent rate, but our queues will not clear.

Some emails are leaving the queue and you think great that is that one gone (some one has called and said i have sent an important mail can you make sure it gets out) but then the SMTP server falls over, i stop it, re start it and that same email is back in the queue.

I couldn't tell you how our mail is set up to go out, but if asked questions i can find the answer and get back.

If any one can give any hints or tips on how to control this queue and hopefully get some of it moving i would be very great full

Thank You
Keith

Dr Zoidberg · 5 Nov 2007 at 23:47

Thanks Jimathy

I will take a look at msexchange.org tomorrow, and put forward the idea of useing dns for direct mail.

As far as i see it at the moment all our outbound mail goes to our ISP and they direct it on, all our inbound mail goes to our ISP and they direct it to us.

i guess this is normal set up (no other experiance)
our emails are [email protected]l internally, but as soon as you send a email to an external address it goes on to the ISp and changes to [email protected]
I assume this would still work using direct DNS,
will go and do some hunting and have a look at that site.

Thanks again

Dr Zoidberg · 6 Nov 2007 at 10:23

Right let me try and fill in some more details then.
Please stick with me, this isnt my system and my experiance with exchange is very limited.

The system has been in place for some time and working fine untill a few weeks ago,
At this time our ISP was contacted and they said they had a problem, (twice in 2 calls a week or so apart)

but if i can confirm the problems are down to them and not at our end that would be a big bonus.

First up we are using the ISP as a smart host, all mail is forwarded through post.ISPname.co.uk

quackers - DNS forward zones ? where are those

stoofa i can find logs telling me all sorts all over the place, any particular logs you have in mind?

Here is a section of a log from yesterday from the smtp virtual server,
I have replaced the IP address in there with XXXXXX
from what i can tell the EHLO -250, mail - 250, RCPT - 250, Quit -240 parts are everything working ok, as for the other parts in there i dont know.

#Software: Microsoft Internet Information Services 6.0
#Version: 1.0
#Date: 2007-11-04 00:01:22
#Fields: time c-ip cs-method cs-uri-stem sc-status
00:05:43 XXXXXX EHLO - 250
00:05:43 XXXXXX MAIL - 250
00:05:43 XXXXXX RCPT - 250
00:05:43 XXXXXX QUIT - 240
00:05:49 XXXXXX EHLO - 250
00:05:49 XXXXXX x-exps - 0
00:05:49 XXXXXX x-link2state - 200
00:05:49 XXXXXX MAIL - 250
00:05:49 XXXXXX RCPT - 250
00:05:49 XXXXXX xexch50 - 354
00:05:49 XXXXXX BDAT - 250
00:05:49 XXXXXX QUIT - 240
00:05:59 XXXXXX EHLO - 250
00:05:59 XXXXXX MAIL - 250
00:05:59 XXXXXX RCPT - 250
00:05:59 XXXXXX QUIT - 240

Dr Zoidberg · 6 Nov 2007 at 10:41

bigredshark said:
just add reverse dns and send using DNS. I work for an ISP and I detest people who decide they need to set our mail relays as smarthosts for their exchange box, I mean, whats the point, you have a mail server then use it! A business ISP should be quite happy to open up the ports for you if they aren't open already, if they aren't then I'd move on sharpish...

So if i turn off the smart host option and set up reverse DNS,
What problems am i likely to inconter with ports?
I am liking this idea as we are still convinced the problem is with our ISP (as they have told us they have a problem) so any chance to not go through there mail servers should be a big help.

Dr Zoidberg · 6 Nov 2007 at 13:09

The reverse DNS looks like fun, think i might have to go banging my head against a few walls but might be our only (sensible) option at this time.

Logs - That is one of the places i had looked, there are a few relating to exchange in there

MSEchange Transport
Queueing engine
event ID 4005

Then goes on to tell time spent doing things, all 0 milli seconds, then the queue length.

Most of these have a ! next to them
Any others are expected notices and not related to exchange.

While on the topic of email, i read a little while ago but 2 methods for incoming mail.

method 1
Everything addressed to @ourdomain.com comes in and is accepted by our server then the front is looked at against our directory and sorted.
This is the method we use

method 2
The name@ is looked at before it is accepted and if the name is not in the directory our server rejects it.

Method 2 looks like the better option to me, any opinions?

Again thank you for all the help and suggestions, i have been dropped in the deep end here and any help is greatfully recieved.

Dr Zoidberg · 6 Nov 2007 at 13:20

Just to add a little note here, it looks to me as though we do already have reverse DNS lookup set up,

On our domain controller i went to
Admin tools > DNS
and this is set with both forward and reverse lookup zones that contain what seems to be details of all the PC's in the building
I assume this is what is needed for the email as well ?

Dr Zoidberg · 6 Nov 2007 at 17:34

Well after 2 phone calls this afternoon i was told to turn it on,
The queue has started to drop in size, but is taking its time,
I have been told our server is going to struggle a little doing this job and that is why we normally go through our ISP, i would say if anything our internet connection is what is going to struggle.

In the forward lookup zone there is a ourcompany.local but not a .com

One of the calls i made was to someone who told me to phone our ISP and check we have a PTR (i think) record or table with them, he then done a look up on our domain himself and told me it was already in place.

The only other thing i have done other than switch the option is to add our ISP's DNS servers to the smtp virtual server settings.

These area already listed in the DNS settings on the domain controller.

Looks like there might still be some things need adjusting here but heading in the right direction hopefully.

Once again thanks for the help

Dr Zoidberg · 6 Nov 2007 at 18:02

Ok i have just thought on something here,

I have switched so our server is doing the work and not sending it all direct to our ISP.

But i have moved from sending to them to using there DNS servers,

Now when they said they had email problems that is all i know, i haven't been told what is causing the problems and this could be there DNS servers,
So would it be an idea to add another DNS server to the list ?

Also am i right in thinking that the mail that was in the queue before i made the switch is not guaranteed to make the switch its self and may remain stuck in the queue? i thought i read that some where.

Dr Zoidberg · 6 Nov 2007 at 19:04

quackers said:
I would imagine any mail stuck in queue should clear, have a go of this:

http://www.checkdns.net/quickcheckdomainf.aspx

put your domain.co.uk in and see what it comes back with

that seems to come back clear on everything, except one
It trys 3 of our ISP's name servers and sasy the 3rd timed out but the other 2 are ok,

Under the mail section it finds both our ISP options and our direct option.

mail server tests

Domain goochandhousego.com has 3 mail-servers.
Checking mail server (PRI=10) mailgate.ourdomain.com [83.104.113.210]
Mail server mailgate.ourdomain.com[83.104.113.210] answers on port 25

<<< 220 ghexchange.ourdomain.local Microsoft ESMTP MAIL Service, Version: 6.0.3790.3959 ready at Tue, 6 Nov 2007 18:49:53 +0000
>>> HELO www.checkdns.net
<<< 250 ourexchange.ourdomain.local Hello [XXX.XX.XX.XXX]
>>> MAIL FROM: <[email protected]>
<<< 250 2.1.0 [email protected]er OK
>>> RCPT TO: <[email protected]>
<<< 250 2.1.5 [email protected]
>>> QUIT
Mail server mailgate.ourdoamin.com [our IP] accepts mail for ourdomain.com

Checking mail server (PRI=50) relay-2.mail.demon.net [XXX.XXX.XX.XX]
Mail server relay-2.mail.demon.net[194.217.242.9] answers on port 25
<<< 220 anchor-relay-1.mail.thus.net ESMTP Postfix
>>> HELO www.checkdns.net
<<< 250 anchor-relay-1.mail.thus.net
>>> MAIL FROM: <[email protected]>
<<< 250 2.1.0 Ok
>>> RCPT TO: <[email protected]>
<<< 250 2.1.5 Ok
>>> QUIT
Mail server relay-2.mail.demon.net [194.217.242.9] accepts mail for our.com

Checking mail server (PRI=50) relay-1.mail.demon.net [xxx.xxx.xxx.xxx]
Mail server relay-1.mail.demon.net[xxx.xxx.xxx.xxx] answers on port 25
<<< 220 lon1-relay-1.mail.thus.net ESMTP Postfix
>>> HELO www.checkdns.net
<<< 250 lon1-relay-1.mail.thus.net
>>> MAIL FROM: <[email protected]>
<<< 250 2.1.0 Ok
>>> RCPT TO: <[email protected]>
<<< 250 2.1.5 Ok
>>> QUIT
Mail server relay-1.mail.demon.net [xxx.xxx.xxx.xxx] accepts mail for ourdomain.com
All MX are configured properly

I have edited out our company details and all IP's that are listed in that, but have left our ISP details in, cant be bothered with not mentioning who it is any more. If the problem is still with them or not.

Dr Zoidberg · 7 Nov 2007 at 00:24

Emails in are still ok, we hav not had a problem with email coming in and this has not changed with this switch

Just got back from a darts match at the pub so maybe not the best time to be logging onto our servers but....

The outbound mail queue is still large, it looks like a big chunck of this is postmaster replys to spam but a good amount of it is still mail waiting to go out,

I am not going to look into it any further tonight, will check again in the morning when back at work.